1. Field
Embodiments of the present invention relate to an electronic parking brake system in a vehicle and a control method thereof, and more particularly, to an electronic parking brake which stably performs a braking operation by estimating a successive range of applying and releasing of the electronic parking brake in a vehicle.
2. Description of the Related Art
In general, a brake system, as a means for decelerating a vehicle speed or stopping a vehicle, is provided at the vehicle for transportation and movement.
The brake system is classified into a driving brake which decelerates and stops a running vehicle, and a parking brake which is used when the vehicle is parked.
Here, the parking brake is an apparatus which keeps a stopped vehicle from moving, and is referred to as a hand brake or a side brake. When a parking brake lever is pulled, a rear brake shoe lever is moved by a parking cable, and a lining is in close contact with a drum, and thus a braking state may be maintained.
The parking brake uses a mechanical structure in which the cable is typically pulled and released using the lever and an operation is released. However, an operating method of the parking brake according to an operation of the parking lever is operated by only a user's intention, and thus when the vehicle is parked on a slope way in a state in which the parking lever is not pulled due to the user's carelessness, the vehicle may move downward, and may cause an unexpected accident. Also, since a driver should operate the parking lever whenever parking or driving the vehicle, it is very inconvenient to use the parking brake, and particularly, it is inconvenient for weak women and elders to use it.
Therefore, recently, an electronic parking brake (EPB) which is controlled with a switch operation instead of the lever operation and thus enhances driver convenience and interior beauty is applied.
In the electronic parking brake (EPB) system, even when the driver does not manually apply the parking brake, the parking brake may be automatically applied or released according to the simple switch operation or a control determination of an electronic control unit which controls an entire operation.
The EPB system includes an actuator which has a motor for generating a braking force, and the electronic control unit (ECU) which drives the actuator. The ECU includes a control part, a plurality of sensor interfaces, a motor drive and a communication module. The ECU drives the actuator according to a switch operation state, and applies or releases the EPB system.
However, a technical development which accurately finds an applying and releasing point of time, and determines an applying time of the brake, and thus reduces a control error is being progressed.